﻿// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved. See License.txt in the project root for license information.

using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;

namespace System.Web.Mvc
{
    public class ModelBinderProviderCollection : Collection<IModelBinderProvider>
    {
        private IResolver<IEnumerable<IModelBinderProvider>> _serviceResolver;

        public ModelBinderProviderCollection()
        {
            _serviceResolver = new MultiServiceResolver<IModelBinderProvider>(() => Items);
        }

        public ModelBinderProviderCollection(IList<IModelBinderProvider> list)
            : base(list)
        {
            _serviceResolver = new MultiServiceResolver<IModelBinderProvider>(() => Items);
        }

        internal ModelBinderProviderCollection(IResolver<IEnumerable<IModelBinderProvider>> resolver, params IModelBinderProvider[] providers)
            : base(providers)
        {
            _serviceResolver = resolver ?? new MultiServiceResolver<IModelBinderProvider>(() => Items);
        }

        private IEnumerable<IModelBinderProvider> CombinedItems
        {
            get { return _serviceResolver.Current; }
        }

        protected override void InsertItem(int index, IModelBinderProvider item)
        {
            if (item == null)
            {
                throw new ArgumentNullException("item");
            }
            base.InsertItem(index, item);
        }

        protected override void SetItem(int index, IModelBinderProvider item)
        {
            if (item == null)
            {
                throw new ArgumentNullException("item");
            }
            base.SetItem(index, item);
        }

        public IModelBinder GetBinder(Type modelType)
        {
            if (modelType == null)
            {
                throw new ArgumentNullException("modelType");
            }

            var modelBinders = from providers in CombinedItems
                               let modelBinder = providers.GetBinder(modelType)
                               where modelBinder != null
                               select modelBinder;

            return modelBinders.FirstOrDefault();
        }
    }
}
